1. Field of the Invention
This invention relates to a method of producing band saw blades for the timber-processing industry, wherein initially a band saw blank is produced from a metal band from a roll, from which subsequently through cutting to length and welding together continuous band saw blades can be produced or provided with hard metal teeth. This invention also relates to a device for implementing the method provided with a saw blade grinding machine, with a supply, a computer and a control unit for inputting a programmed tooth geometry where the program stages necessary for production, with a grinding blade which can be moved at least along an x axis and a y axis, as well as with a guide for guiding the metal bands to be ground and an advancing device to move the metal bands to be ground.
2. Discussion of Related Art
Historically, saw blades made by craftsmen were originally always ground directly from a metal sheet or a metal band, but this production method has been abandoned in industrial manufacturing for about 50 years. Then, band saw blades were produced as blanks in a first production stage through stamping out a metal band. Here, a single metal band from a roll or a reel is continuously stamped and rolled up again. In a following stage this blank is ground to a final form by a grinding machine and then appropriately deflected and welded together to form continuous band saw blades. After application of the appropriate hard metal teeth, further grinding takes place.
In published German Patent Application DE 19 517 65, this production process is described as the state of the art.
From Swedish Patent Specification SE 524430, a method is known for producing saw blades through a sequence of hole stampings. Austrian Patent Specification AT-385453B also discloses a production method in which the saw blade is stamped as a blank in a first stage, in a second stamping process teeth are formed, and in a final working stage the teeth are ground into their end form.
In many cases, the saw blade blanks are not self-produced but are obtained from a stamping plant. Thus, depending on other requirements in each case, stamping tools are produced and the stamped saw blade blanks are stored in the form of rolled metal bands. Given the number of possible saw tooth geometries with different tooth shapes and different tooth spacings, this requires relatively large stocks to be held and correspondingly managed. If the required blanks are not in stock, users often have to put up with relatively long delivery times, particularly with smaller order quantities where it is hardly worthwhile having a required material made just for this order quantity.
In the current production method, the blanks are inserted into the grinding machine and individually ground with precision into their final form. Because current grinding machines are very powerful, the grinding process is now relatively fast. Working on several blanks at the same time is thus conceivable. Although the performance of the machines would allow this, it cannot be carried at a reasonable expense. If pre-stamped bands are combined, it would not only be necessary to ensure that they lie level on each other but also that they are fed accurately spaced, such as without displacement in the longitudinal direction over the entire length of all bands. Realistically, this is not feasible.